In the April 2003 issue of MM&FF we covered the installation of ProCharger's P1-SC supercharger on our resident '90 Mustang GT. As far as project cars go, we haven't bothered to give this one a name yet, but we've continued to modify it with a Cobra R four-wheel disc brake upgrade from Ford Racing. With 330 hp at the wheels of the little mare, we definitely had to do something about the stopping situation and the FRPP kit worked like a charm.
This time around we've decided to chuck the stock shorty headers in exchange for some long-tubes, but we didn't stop there. We also needed to get the pony in compliance with the state of New Jersey's emissions requirements and we accomplished that with a set of high-flow catalytic converters. Lastly, the venerable Flowmaster mufflers and stock cat-back pipes were traded for a true 2.5-inch cat-back system.
Choosing an aftermarket exhaust can improve both the sound and performance of your pony, and with what we hope to do with it in the future, we looked for an exhaust upgrade that wouldn't be a restriction later on.
When it comes to exhaust tones, just about every manufacturer has its own unique signature. The best way to choose one that you like is to go to your local cruise-in or better yet, visit a Fun Ford Weekend or NMRA event. Listen to the cars as they do their burnouts. Listen to them go down the track and then head to the pits. Find the cars that sound good to you and then find out what they're running. Granted you might like the sound of a big-block Pro car, but running open headers on the street really isn't an option, not to mention that 4-inch collectors and 2-inch primaries probably aren't the best setup for your bolt-on street car.
Our pony's combination is somewhat unusual at this point. It's a stock five-liter from intake to pan, but we're cramming 10 psi of boost through it with some help from ATI. Someday, we would like to get some nice cylinder heads and a hotter camshaft, but for now she's mostly stock. We do have an intake manifold on the way and with all of these parts, we're expecting a power output in the neighborhood of 400-450 at the rear wheels. With those plans in mind we decided to go with long-tube headers and a full 2.5-inch exhaust system.
The long-tube headers we selected are from Bassani (PN 5092R), are chrome plated and retail for $731.50. These optimum-length, 14-gauge carbon steel tubes are mandrel bent and step up in size from a 1 5/8-inch diameter to 1 3/4 inches. This stepped design keeps exhaust from reverting back up the tube and the smaller sized tube off the head maintains torque, while the larger tube downstream aids horsepower. The individual tubes slip-fit into Bassani's exclusive "Extractor Collector," which induces a scavenging effect, further improving performance. The headers come with instructions and all necessary parts for the installation from bolts to gaskets and even antiseize.
Bassani has a new line of exhaust components called BX, which replaces Bassani's standard, stainless steel tubing with mild steel construction wherever possible to reduce the cost and price of the part. We used a BX shorty X-pipe (PN 50933R) equipped with high-flow catalytic converters. With New Jersey vehicle inspections being the brutal tests that they are, we averted potential problems by going with the proper cats. The BX X-pipes are mandrel bent and made from aluminized steel for corrosion protection. Our '90 GT was already running an off-road X-pipe, and we happen to like the change in tone that occurs when using one, so that is why we chose the BX unit.
MM&FF's Procharged Pony has...
MM&FF's Procharged Pony has quite a few miles on her, but still runs like a top. We began the exhaust installation by removing the spark plugs. If your wires are not marked by cylinder, do it as you remove each plug.
Moving below, we sprayed the...
Moving below, we sprayed the nuts and bolts with a penetrating oil and then unbolted the cat-back and X-pipe.
This tube from the air pump...
This tube from the air pump must also be removed. Bassani supplies a new one along with clamps and hoses to connect it.